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-   -   How to separate the porous region? (http://www.cfd-online.com/Forums/openfoam/114072-how-separate-porous-region.html)

hesamgh March 4, 2013 04:01

How to separate the porous region?
 
hi

would you please explain me how do you separate the porous region in opoenFoam?


thanks


Quote:

Originally Posted by Se9a (Post 285916)
Hello!
I try to use a porousSimpleFoam solver to simulate a flow in a 2D channel from two equal parts, a free flow part and a porous part (wall's type set in the 'slip' for simplicity):

http://img-fotki.yandex.ru/get/5601/...61536200_L.jpg

Base case is a angleDictImplicit.

My results are a good p, but strange oscillating U.
On the next sctrutured mesh:
http://img-fotki.yandex.ru/get/5106/...c6b86593_L.jpg

I get this solution:
http://img-fotki.yandex.ru/get/5701/...c78ed4bd_L.jpg

Velocity field is:
http://img-fotki.yandex.ru/get/5802/...b0d0a7fc_L.jpg


One can see what velocity is good but slightly oscillated on porous boundary. So, question is:

Are such oscillations caused by a stepwise porous source? If yes, how can I specify smooth porous source?



But more bad situation have place on non-structured mesh.
Mesh is
http://img-fotki.yandex.ru/get/5602/...b921d596_L.jpg

Solution is:
http://img-fotki.yandex.ru/get/6001/...6741e4eb_L.jpg

http://img-fotki.yandex.ru/get/5001/...3b4da787_L.jpg

One can see very oscillating velocity in the porous region.
So, why this happens? Non-orthogonal correction not helped.

Thanks.


wyldckat March 4, 2013 18:58

Greetings Hesam and welcome to the forum!

I've moved your post to a new thread, because the other thread was already a bit old.

As for your question, please study the following two tutorials:
  • OpenFOAM's tutorial "incompressible/porousSimpleFoam/angledDuctImplicit". It uses the cell zone definitions directly in "blockMeshDict".
  • This one is an adaptation of the previous tutorial, but using snappyHexMesh: http://www.cfd-online.com/Forums/ope...tml#post408279
Best regards,
Bruno


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